Modular pump housing

ABSTRACT

A modular pump housing includes: a pumping chamber, substantially cylindrical about a pumping axis and including an opening for the insertion of a piston and a base opposite the opening; a face suitable for attaching a fluid interface thereto; and a conduit connecting the base with the face. Using a further disclosed process, the diameter of the chamber can be selected during manufacture without changing the external measurements of the body. A solenoid valve can be attached using the fluid interface. If a solenoid valve is not used, an additional conduit is provided through a sidewall of the chamber for connecting the latter with the fluid interface.

The present invention relates to the field of piston pumps used in automatic sampling, in particular pumps of the syringe type used for taking a blood sample with a view to analysis thereof by automatic apparatus.

The patent FR 2 974 155 describes such pumps.

However, these pumps are particularly expensive to manufacture, since they must be manufactured in various configurations, according to the pumping volume necessary and depending on whether they are equipped with a solenoid valve or not.

The aim of the invention is to propose means for manufacturing reliable pumps at low cost.

To achieve its aim, the invention proposes a pump body characterised in that it comprises:

-   -   a pumping chamber substantially cylindrical around a pumping         axis, comprising an opening for axially introducing a piston         therein and a bottom axially opposite to the opening;     -   a connection face, preferably substantially planar, preferably         parallel to the axis;     -   an angled pipe connecting the bottom to this face; and     -   means for fixing a fluid interface against the face.

The means for fixing the interface may be devoid of thread and, preferably, are smooth bores.

Advantageously, the pump body comprises a base and means for fixing said base to a frame. The means for fixing the base may be devoid of thread and are preferably smooth bores.

The body may further comprise a lateral pipe connecting a lateral wall of the chamber to the connection face.

The invention also relates to a family of pump bodies according to the invention, characterised in that it comprises a plurality of pump bodies having identical outside dimensions, each pump body having a specific chamber diameter.

The invention also relates to a pumping assembly characterised in that it comprises a pump body according to the invention and a fluid interface fixed to the connection face of the body. Such a pumping assembly may comprise a pump body having a lateral pipe connecting a lateral wall of the chamber to the connection face, a fluid interface and a solenoid valve fluidically connected to the connection face by the interface.

The invention also relates to a pump comprising a pumping assembly according to the invention.

The invention also relates to a method for manufacturing a pump body from a family according to the invention, characterised in that:

-   -   a single external mould is used;     -   a chamber core corresponding to a required chamber diameter is         chosen; and     -   it is chosen or not to use a core for producing the lateral         pipe.

Several embodiments of the invention will be described below, by way of non-limitative examples, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of an assembly comprising a pump body according to a first embodiment of the invention and a solenoid valve fixed to this pump body;

FIG. 2 is an elevation and front view of the pump body of FIG. 1;

FIG. 3 is a longitudinal section, in elevation, along the plane III-III in FIG. 2, of the assembly in FIG. 1;

FIG. 4 is a view similar to the one in FIG. 3, in which the pump body comprises a chamber with a diameter less than that of the chamber in FIG. 3;

FIG. 5 is a perspective view of a pump body according to a second embodiment of the invention, without a solenoid valve;

FIG. 6 is a view similar to the perspective view in FIG. 5, in which the body is further shown cut longitudinally, along the plane VI-VI in FIG. 7;

FIG. 7 is a front view in elevation of the pump body of FIG. 5;

FIG. 8 shows four cross sections along VI-VI, each of a pump body with a respective chamber diameter; and

FIG. 9 illustrates a pump equipped with a body according to the invention.

In the description, the terms vertical and front, in particular, are attributed arbitrarily, according to the arrangement of the main figures. These terms are not limitative, and the elements described may have a different arrangement when they are implemented on an apparatus.

FIGS. 1 to 4 illustrate a pump body 10 designed to be mounted with a solenoid valve 11 on a pump 100. In the example illustrated, an interface piece 12 provides a fluid connection between the body 10 and the valve 11. This interface piece may be an independent piece, or may be an integral part of the solenoid valve 11.

The body 10 fits within a substantially cylindrical shape, of diameter D10, around a vertical axis X10. This cylindrical shape is truncated in a top part 14 by two flats forming two opposite faces 15, 16, planar, vertical and parallel to each other. The axis X10 is equidistant from the two faces 15, 16.

Under the top part 14, the body comprises a base 17 substantially cylindrical around the axis X10. The top part 14 extends vertically upwards from the base 17. The thickness E17 of the base is small in relation to the total height H10 of the body and the diameter D10 of the body. In the example illustrated, E17<H10/4, and E17<D10/4. The base comprises, at either side of the top part, bores 18 passing vertically through the base. As illustrated in FIG. 9, these bores 18 are designed to fix and position the body 10 on a central piece 40 of the pump 100. By virtue of this arrangement, it is not necessary for the body to comprise a thread to fix it to a frame.

Bores 19 are formed in the top part 14 of the body, perpendicular to the opposite faces 15, 16.

The solenoid valve 11, through its interface 12, is fixed to a front face 15, among the opposite faces 15, 16, of the body 10, so that it extends horizontally from this front face 15. The interface 12 has a substantially rectangular vertical section. It comprises a vertical front face 21, against which the solenoid valve 11 is fixed, so that the latter extends horizontally from the front face 21 of the interface 12. The solenoid valve 11 has a substantially rectangular vertical section, substantially identical to that of the interface, so that the interface and the solenoid valve form an assembly with a substantially constant vertical section, in line with one another.

A counter-piece 22 is fixed against the rear face 16, among the opposite faces 15, 16, of the body 10. Each bore 19, formed in the top part 14 of the body, is disposed so that it emerges firstly on the front face 15, facing the interface 12, and secondly in the face on the rear face 16, opposite the counter-piece 22. Each bore 19 is further formed so as to introduce a fixing rod, not shown in the figures, in a tight fit therein. This rod passes through the body 10, holding it gripped between the interface 12 and the counter-piece 22, fixing them to the body. By virtue of this arrangement, it is not necessary for the body to comprise a thread in order to fix the interface 12 and/or the counter-piece 22 therein.

The body further comprises a pumping chamber 26, substantially cylindrical around the axis X10. The chamber comprises an opening 25 in a bottom face 27 of the body, so as to be able to introduce a piston 41 therein, shown in FIG. 9. The chamber extends through the base 17 as far as the top part 14 of the body 10. It comprises a frustoconical-shaped top end 28, forming a bottom 28 axially opposite to the opening 25. The diameter of the frustoconical bottom 28 decreases in the upward direction. The body 10 further comprises an angled pipe 29 fluidically connecting the top of the top end 29 of the chamber to the front face 15 of the body, and beyond, to the fluid interface 12. The pipe 29 serves as both inlet and outlet for the fluid in the pumping chamber 26. The distribution of the fluid is provided by the solenoid valve 11. The chamber 26 has a main diameter D26, measured in the part provided for the sliding of the piston 41, and a height H26, measured between the bottom face 17 of the base 17 and the base of the frustoconical end 28.

As illustrated in FIGS. 3 and 4, a width L14 of the body, between the two faces 15, 16 of its top part 14, is provided for chambers with a plurality of chamber diameters D26. As illustrated, for the same width L14, the diameter D26 of the chamber 26 in FIG. 4 is smaller than that of the chamber 26 in FIG. 3. Thus, for identical outside dimensions, it is possible to manufacture a plurality of bodies with different chamber volumes, each suited to a specific use.

The chambers 26 in FIGS. 3 and 4 further have the same height H26. Thus only the diameter of the piston must be adapted to the diameter D26 of the chamber, the possible travel of the piston in the chamber remaining substantially the same. Thus, in order to modify the pumping volume in a pumping device 10-12, it suffices to modify the piston/pump body pair, the rest of the device being identical.

A second embodiment will now be described for a body according to the invention, in the way that it differs from the previous embodiment, with reference to FIGS. 5 to 9.

In FIGS. 5 to 9, the body 10 is designed to be mounted without solenoid valve. Thus, apart from the angled pipe, it comprises a lateral pipe 30, connecting a lateral wall 32 of the chamber, in the cylindrical zone of main diameter D26, to the front face 15. The interface 12 used in this second embodiment is adapted to extend each of the pipes 29, 30 by respective pipes 34, 35, in order to connect them to the rest of the apparatus. The chamber is therefore connected to the front face 15 by two pipes, one serving for the admission of fluid into the chamber, the other pipe serving for the discharge of the fluid. The interface 12 used in this second embodiment is fixed by two screws passing through the bores 19.

As illustrated in FIG. 8, and as previously described with reference to FIGS. 3 and 4, it is possible to produce a family of pump bodies each having a different chamber volume, solely by modifying the diameter D26 of the chamber 26. In the example illustrated in FIG. 8, the family comprises four pump bodies 10, adapted to function without solenoid valve, each having a specific chamber diameter D26.

Thus the body 10 of the second embodiment, illustrated in FIGS. 5 to 8, differs from the body according to the first embodiment illustrated in FIGS. 1 to 4 solely in that it comprises a second pipe 30 formed in a lateral wall of the chamber 26.

According to the invention, it is therefore possible to manufacture pumping assemblies with or without solenoid valve, having specific chamber volumes, but wherein the pump bodies 10 all have the same external diameters D10, H10, L14. In order to manufacture such a pump body 10, it suffices to have a single external mould, and a first specific core suitable for forming a chamber with a given diameter D26 and a core used solely for producing the lateral pipe, if necessary. The other cores preferably remain identical whatever the type of pump body 10.

Furthermore, the body being fixed by bores, without thread, it can be manufactured by moulding with more precision and at lower cost. This is because the moulding of a thread is a complex operation; poor filling of material around the core forming the mould for the thread produces incipient ruptures in the injected material, which reduces the reliability of the part thus manufactured, and may lead to the scrapping of numerous parts, which increases the manufacturing costs thereof.

Naturally the invention is not limited to the preferred embodiments that have just been described but, on the contrary, the invention is defined by the following claims.

It will be clear in fact to a person skilled in the art that various modifications can be made to the embodiments described above, in the light of the teaching that has just been disclosed to him.

Thus the connection face may have a form other than planar, provided that it can be mounted sealingly against the interface. It may be cylindrical or spherical. A planar connection face may comprise a planar surface and recesses adapted to allow manufacture by moulding, in particular to avoid excessive thicknesses of the walls. 

1. Pump body (10), comprising: a pumping chamber (26) substantially cylindrical around a pumping axis (X10), comprising an opening for a piston to be introduced axially therein and a bottom (28) axially opposite said opening; a connection face (15); an angled pipe (29) connecting said bottom (28) to said face (15); and means (19) for fixing a fluid interface (12) against said face (15).
 2. Pump body according to claim 1, wherein the means (19) for fixing the interface (12) are devoid of thread and are preferably smooth bores.
 3. Pump body according to claim 1, further comprising a base (17) and means (18) for fixing said base to a frame.
 4. Pump body according to claim 3, wherein the means (18) for fixing the base (17) are devoid of thread.
 5. Pump body according to claim 1, further comprising a lateral pipe (30) connecting a lateral wall (32) of the chamber (26) to the connection face (15).
 6. Family of pump bodies according to claim 1, further comprising a plurality of pump bodies having identical outside dimensions, each pump body having a specific chamber diameter (D26).
 7. Pumping assembly, comprising a pump body (10) according to claim 1 and a fluid interface (12) fixed to the connection face (15) of said body.
 8. Pumping assembly, comprising a pump body (10) according to claim 1, a solenoid valve (11) fluidically connected to the connection face (15) of said body by said interface (12).
 9. Pumping assembly according to claim 8, wherein the fluid interface forms an integral part of the solenoid valve.
 10. Pump (100) comprising a pumping assembly according to claim
 7. 11. Method for manufacturing a pump body among a family according to claim 6, wherein: a single external mould is used; a chamber core corresponding to a required chamber diameter (D26) is chosen; and it is chosen to use or not a core for producing a lateral pipe (30).
 12. The pump body of claim 1, wherein the connection face is substantially planar.
 13. The pump body of claim 12, wherein the connection face is parallel to said axis (X10).
 14. The pump body according to claim 2, further comprising a base (17) and means (18) for fixing said base to a frame.
 15. The pump body of claim 4, wherein the means (18) for fixing the base (17) are smooth bores.
 16. Pump body according to claim 2, further comprising a lateral pipe (30) connecting a lateral wall (32) of the chamber (26) to the connection face (15).
 17. Pump body according to claim 3, further comprising a lateral pipe (30) connecting a lateral wall (32) of the chamber (26) to the connection face (15).
 18. Pump body according to claim 4, further comprising a lateral pipe (30) connecting a lateral wall (32) of the chamber (26) to the connection face (15).
 19. Family of pump bodies according to claim 2, further comprising a plurality of pump bodies having identical outside dimensions, each pump body having a specific chamber diameter (D26).
 20. Family of pump bodies according to claim 3, further comprising a plurality of pump bodies having identical outside dimensions, each pump body having a specific chamber diameter (D26). 